Automatic electrical controls for household and similar use – Part 2-7: Particular requirements for timers and time switches
|Publication Date:||1 April 2008|
|ICS Code (Automatic controls for household use):||97.120|
In general, this standard applies to timers and time switches for household and similar use that may use electricity, gas, oil, solid fuel, solar thermal energy, etc. or a combination thereof, including heating, air conditioning and similar applications.
Throughout this standard the word "timers" means timers and time switches, unless the type is specifically mentioned.
Devices which only indicate time or passage of time are not included.
This standard does not apply to multi-functional controls having an integrated timing function which is not capable of being tested as a separate timing device.
This standard does not apply to time-delay switches (T.D.S.) within the scope of IEC 669-2-3.
This standard applies to the inherent safety, to the operating values, operating sequences where such are associated with equipment protection, and to the testing of timers used in, on or in association with household and similar equipment.
This standard is also applicable to timers for appliances within the scope of IEC 335.
This standard applies to manual controls when such are electrically and/or mechanically integral with timers.
Manual switches not forming part of an automatic control shall comply with IEC 328.
This standard applies to controls with a rated voltage not exceeding 660 V and a rated current not exceeding 63 A.
This standard does not take into account the response value of an automatic action of a control, if such a response value is dependent upon the method of mounting the control in the equipment. If a response value is of significant purpose for the safety of the user or surroundings, the value defined in the appropriate household equipment standard or as determined by the manufacturer shall apply.
Requirements for electronics contained in Appendix H are under consideration.